Get ready to revolutionize your virtual reality experience with the SlimeVR Butterfly Trackers! These innovative, full-body VR trackers are designed to take your gaming, motion capture, and VTubing adventures to the next level. But here's the real game-changer: they offer an incredible 48-hour battery life, making them a true powerhouse in the world of VR tracking.
Developed by the talented team at SlimeVR in Rotterdam, these open-hardware trackers utilize IMU technology for precise, absolute rotation tracking. The best part? You won't need any base stations, cameras, Wi-Fi, or Bluetooth to enjoy their full-body positional tracking capabilities.
Each tracker is a marvel of engineering, featuring an IMU that transmits data over a custom 2.4 GHz ESB protocol. This protocol, supported by a dedicated dongle, ensures seamless tracking and eliminates occlusion issues. The trackers are based on the nRF52833 wireless MCU from Nordic Semi, and their unique split "butterfly" design is a masterpiece of compactness and comfort. By placing the PCB and 90 mAh battery side-by-side, the team achieved an astonishing thickness of under 7 mm and a weight of less than 10 grams per tracker. A flexible interconnect further enhances comfort, making them perfect for extended VR sessions or even wearing under clothing.
The SlimeVR Butterfly Trackers offer a refresh rate of 100-200 Hz and an impressive latency of less than 15 ms. With USB-C charging and OTA firmware updates, these trackers are not just powerful but also incredibly convenient.
But wait, there's more! The team behind these trackers has a history of innovation. Their original SlimeVR trackers, which raised over 9 million dollars, were based on Espressif ESP32/ESP8266 modules. While those trackers were great for DIY enthusiasts, they had a major drawback: power consumption. The new Butterfly Trackers address this issue head-on by using the Nordic Semiconductor nRF52833 SoC and the Enhanced ShockBurst (ESB) protocol, which is low-latency and low-power. This allows the trackers to run for over 48 hours on a tiny 90 mAh battery, a true feat of engineering.
And this is the part most people miss: the 7mm thin design. The team's clever placement of the PCB and battery side-by-side, connected by a flexible bridge, allows the tracker to conform to your body. This design choice not only reduces thickness but also enhances comfort, especially when you're lying down in VR or wearing them under tight clothing.
Now, let's talk about the software. The Butterfly trackers run on the Smol Slime firmware, which was originally a community-led project designed to manage power limitations. The SlimeVR Server, a cross-platform application, acts as the central hub, receiving raw rotation data and using advanced algorithms like Autobone and Stay Aligned for precise skeletal calibration and drift compensation. The software can handle up to 20 trackers, ensuring extreme precision in your VR experiences.
To bring your movements to life in games like VRChat, Blade & Sorcery, or Minecraft, the Server communicates with the game using an OpenVR Driver or the OSC protocol. This allows for seamless integration, making your VR adventures truly immersive.
You can get your hands on the SlimeVR Butterfly Trackers through Crowd Supply, with bundle options starting from the $279 Core Set (6 trackers + dongle) to the $788 17-tracker Motion Capture Set. There's also a $499 Sakura Edition with a charging dock, and you can purchase individual trackers, dongles, and accessories separately. Shipping is scheduled to begin on August 31, 2026, so mark your calendars!
These trackers are a testament to the innovation and dedication of the SlimeVR team. With their impressive battery life, ultra-slim design, and advanced software, they're set to redefine the VR tracking experience.
What do you think? Are you ready to embrace the future of VR tracking with the SlimeVR Butterfly Trackers? We'd love to hear your thoughts and experiences in the comments!
